Stem Cells in Adult and Embryo Flashcards
What was the result of taking a blastomere from a sea urchin embryo at the 2 cell stage?
Became smaller but normal larva
Define totipotency
Can differentiate into embryonic and extra-embryonic cell types
Define pluripotency
Can differentiate into any of 3 germ layers
Define multipotency
Can differentiate into multiple closely-related cells
Define unipotency
Can differentiate into only one cell type
What are the factors controlling neurogenesis?
Modes of division and cell cycle length - cell cycle regulators
Transcription factors
Epigenetic factors
Diffusible signals
What is symmetric division of a neural progenitor?
Vertical cleavage
Proliferative
What is asymmetric division of a neural progenitor?
Horizontal cleavage
Neurogenic
What is symmetric terminal division of a neural progenitor?
Vertical cleavage
Neurogenic - 2 neurons made
What is the effect of Notch?
Keeps progenitor in undifferentiated state
What is the effect of cell cycle lengthening?
More cortical progenitors
What is the effect of cell cycle shortening?
More self-renewing divisions
What is Nestin a marker for, and when is it seen?
Neural stem cells
3 hours
What is Tuj a marker for, and when is it seen?
Cells that become neurons
3 days
What is GFAP a marker for, and when is it seen?
Cells that become astrocytes
10 days
What is O4 a marker for?
Oligodendrocytes
Name 2 intrinsic transcription factors differentially activated by external factors controlling neurogenesis
Pax6
Nkx2.2
What are the types of stem cells and what are their properties?
Adult - pools of multipotent SCs in certain tissues
Embryonic - pluripotent SCs in blastocyst
Induced - reprogrammed somatic cells
Where are new neurons generated in the adult brain and where do they migrate to?
SVZ of lateral ventricles
Through rostral medullary stream - to olfactory bulb - become interneurons
What do radial glial-like cells in the SVZ of the adult brain become and where do they migrate to?
Transient amplifying cells - become neuroblasts
Through tube formed by astrocytes - to olfactory bulb - become interneurons
Where in the adult hippocampus does neurogenesis occur?
Subgranular zone (SGZ) in dentate gyrus
What is the process of neurogenesis in the SGZ?
Radial and non-radial precursors become immediate progenitors - become neuroblasts - migrate to inner cell layer - become dentate gyrus granule cells
How can the effect of a novel enriched environment on neurogenesis be shown?
Inject BrdU into adult mice - label for newborn neurons
More BrdU+ neurons in mice exposed to novel enriched environment
What are the Yamanaka factors and how are they used?
Oct3/4, Sox2, Klf4, c-Myc
Generate iPS cells from human dermal fibroblasts
What are some functional tests of vision restoration in mice?
Synapse formation - electron microscopy
Cell responses to light - patch clamping
Visually-evoked visual cortex activity - intrinsic cortical imaging
What are some behavioural tests of vision restoration in mice?
Visual responses - optokinetic head tracking
Vision - water maze
What are the difficulties in repairing end stage retinal degeneration?
Loss of supporting cytoarchitecture
Re-wiring of remaining neurons
Scarring
Immune reaction
